This invention relates to an actuator for converting rectilinear motion to alternating, opposite direction, rotary motion and, more particularly, to such an actuator adapted for use in actuating mechanisms such as automobile door locks and the like.
Many mechanical devices require the provision of positive, rotational motion alternating in opposite directions. It is desirable that such motion be produced as demanded without constant operation or energy use. One way to accomplish that result is to convert reciprocal motion to alternating, opposite direction, rotary motion utilizing a reciprocal camming element operating a pivot member and many prior devices have been developed for such purposes. However, many of the prior devices included complex, intricate mechanisms which could not reliably or positively reposition the camming element for subsequent operation without contact with the pivot member. This subjected the pivot member to wear and allowed unintended motion of the pivot member. Also, the camming element and pivot member were often not reliably and securely supported and were subject to wear and frequent breakdown.
Such alternating rotational motion has been found especially useful for remote operation of vehicle door locks. A particular objective with such locks is to either lock or unlock a door by operation of the actuator mechanisms in the desired, predetermined direction only if the door is not already locked or unlocked. The actuator should not operate to unlock the door if the door is already locked unless the operator deliberately chooses to operate the actuator in the "unlock" direction and vice-versa. However, the prior devices failed to provide these features and especially the positive rotational actuation in only a desired direction upon demand. The prior devices generally failed to provide any indication of, or control over, the direction of rotational movement. In addition, the particular application to door lock mechanisms requires the ability to operate safely in a confined space while overcoming the drawbacks and providing the features mentioned.